The Mycoplasma are a wide-spread group of bacteria. Species such as M. pneumoniae, and M. genitalium cause disease in humans. Related species cause disease in plants. M. bovis is considered one of the more pathogenic species and causes pneumonia, mastitis and arthritis in cattle. In research laboratories, Mycoplasma species are frequent contaminants in cell cultures.
Mycoplasma are characterized by the absence of a cell wall. Unfortunately, the most important group of antibiotics, the beta lactams, (which include both the penicillins and the cephalosporins) function by inhibiting cell wall synthesis. With important antibiotics such as these unavailable for the treatment of mycoplasma infections, there is a need for new and rapid methods and apparatus for the detection of these species so that they may be quickly detected on occurrence and controlled or eradicated before the spread thereof. In summary, Mycoplasma and particularly M. bovis is a substantial threat to dairies and an unaddressed. Mycoplasma infection can lead to business foreclosure.
Major deficiencies exist today with the mycoplasma diagnostic tests available to dairymen. For example, none of the current tests can provide dairymen with an immediate (e.g., within 20 minute—while the cows are still in the milking parlor) ability to discriminate, among cows that have been exposed to mycoplasma, those that are suffering with an infection from those cows who have not come in contact with mycoplasma. Current culture tests take up to 10 days and cannot discriminate antibiotic resistant mycoplasma from the closely related Acholeplasma that has identical agar plate morphology, but is treatable with antibiotics. Another problem with current culture methods is that these tests cannot be performed on a milk sample containing mycoplasma that has been frozen. Freezing reduces the ability of mycoplasma to grow on agar plates. Further, since animals that are positive for mycoplasma only shed organism intermittently, many tests for antigen, either viable intact organism or organism fragments, will frequently suggest an animal is negative for mycoplasma when indeed the animal has a current infection.
In summary, the industry needs a test that can provide results in 20 minutes or less, a test that can be performed on frozen milk samples, and a test system that can discriminate M. bovis from Acholeplasma. The test must also be able to discriminate animals that have been exposed and those with a current or recent infection, and include detecting those mycoplasma positive animals that are intermittently shedding live organism. Furthermore, the industry needs some combination of rapid tests that work directly and indirectly by different mechanisms, which used together provide reliable evidence that an animal is positive for mycoplasma. In particular embodiments, some combination of tests that probe for antigen and the cow's immune response would be ideal for confirming infection.
The present invention overcomes previous shortcomings in the art by providing methods and compositions for the rapid detection of mycoplasma infection in animals.